def add(a, b):
    print(f"adding {a} + {b}")
    return a + b


def subtract(a, b):
    print(f"subracting {a} - {b}")
    return a - b


def multiply(a, b):
    print(f"multiplying {a} * {b}")
    return a * b


def divide(a, b):
    print(f"dividing {a}/{b}")
    return a/b


print("let's do some math with just functions!")

age = add(30, 5)
height = subtract(78, 4)
weight = multiply(90, 2)
iq = divide(100, 2)

print(f"age: {age}, height: {height}, weight: {weight}, IQ: {iq}")


print("here is a puzzle.")

what = add(age, subtract(height, multiply(weight, divide(iq, 2))))

print("that becomes: ", what, "can you do it by hand?")